WASHINGTON –– James Clapper, the longtime director of national intelligence under President Barack Obama, said unequivocally Sunday that Donald Trump’s home and office were not wiretapped before the presidential election last year.

Clapper, who was director for more than six years before he left in January, also said he knew of no evidence that members of Trump’s campaign had colluded with Russia during the election campaign and that no suggestion that they had was made in a January report on the subject.

“We did not include anything in our report that had any reflection of collusion between members of the Trump campaign and the Russians,” he said on NBC’s “Meet the Press.” “There was no evidence of that included in our report. We had no evidence of such collusion.”

Clapper said, however, that he still agrees with that report’s conclusion that Russian President Vladimir Putin had developed a “clear preference” for Trump and that the release of Democratic operatives’ emails stolen by Russian computer hackers was part of the effort to support the Republican candidate. An unclassified version of the report was made public Jan. 6, two weeks before Trump was sworn in as president.

Earlier Sunday, the White House demanded that the Republican-led Congress expand its investigation into Russian meddling to include Trump’s allegation that Obama ordered wiretaps on Trump’s New York offices. Trump made the claim Saturday via Twitter, but offered no evidence for the claim. An Obama spokesman, Kevin Lewis, said the allegation was “simply false.”

Clapper was categorical in his television interview.

“There was no such wiretap activity mounted against the president, the president-elect at the time, or as a candidate, or against his campaign,” Clapper said.

Clapper also denied that the Foreign Intelligence Surveillance Court had authorized any wiretap. “I can deny it,” he said. But he said he couldn’t speak for “other authorized entities in the government or a state or local entity.”

Allegations that Trump’s team possibly colluded with Russia have cast a shadow over his presidency.

Last week, Attorney General Jeff Sessions was forced to withdraw from Justice Department investigations into Russian influence after revelations that he offered possibly misleading testimony during his confirmation hearing about his contacts with Russian Ambassador Sergey Kislyak. In February, Trump fired national security adviser Michael Flynn for misleading Vice President Mike Pence about his contacts with Kislyak.

White House deputy press secretary Sarah Huckabee Sanders defended Trump’s wiretap claim and the White House call for an investigation Sunday on ABC’s “This Week.” “I think he is going off information he’s seen that has led him to believe that this is a very real potential,” she said. “The American people have a right to know if this took place.”

Democrats slammed Trump for the accusation.

“The president is the deflector-in-chief — anything to change the subject from where the heat is,” House Majority Leader Nancy Pelosi, D-Calif., said on CNN’s “State of the Union.” “As one who has been engaged in intelligence … I can tell you it’s just ridiculous for President Trump to say President Obama would ever order any wiretap of an American citizen — any president — we don’t do that.”

“To make that type of claim without any evidence is, I think, very reckless,” Sen. Mark Warner, D-Va., the top Democrat on the Senate Intelligence Committee, said on CBS’s “Face the Nation.”

Leon Panetta, who was as CIA director and secretary of defense under Obama, said on “Face the Nation” that the controversy over Russia and Trump was damaging to the country’s national security.

“Every time these things happen, every time he tweets, every time these issues come up that indicate that, you know, there’s obviously something to this Russian issue and the administration is not cooperating, when that happens, when he accuses a past president of wiretapping without any evidence of that being the case, it makes us vulnerable,” Panetta said. “It weakens the United States, and it makes us vulnerable to our enemies. That’s the danger.”